[Rubygems-developers] Ability to require jar-files

Michael Studman me at michaelstudman.com
Mon Oct 2 19:07:10 EDT 2006

> JRuby-specific extensions to RubyGems. One small feature that would be 
> very welcome for us would be to make it possible to require jar-files in 
> the regular load-path. We have added support for JRuby such that executing
> require 'bin_ext'
> will search for bin_ext.rb and bin_ext.jar on the load path. If the same 
> would be possible with gems, it would mean we can package extensions and 
> people can use them the same way .so-extensions are used.
I think this is all already working. I'm nearly done porting the 
.so-extension of a certain Ruby gem to a Java  extension and I can get 
JRuby & Gem loading my jar just fine through "require 'bin_ext'" (which 
finds the jar at 
I can also confirm that require_gem with a version requirement loads the 
right jar too!

It was a pleasant surprise that this all just worked for me. I had to 
check multiple times to ensure I hadn't inadvertently sprinkled some 
Java classpath pixy dust which made it all work when it shouldn't have.

The only problem I had when creating this JRuby-specific variant of the 
Gem was that there was no Gem::Platform::Java or Gem::Platform::JRuby to 
use for the spec's platform (I'm just using "java" in the mean time).

If I've misunderstood what you're actually asking here, Ola, then sorry 
for the line noise.


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